18ct gold is one of the most popular choices for high-quality jewellery in the UK — used in engagement rings, necklaces, and luxury pieces. At 75% pure gold, it's significantly more valuable per gram than 9ct gold, and with gold prices near historic highs, now is an excellent time to find out what yours is worth.
This guide explains exactly how 18ct gold is valued, how to calculate what yours is worth, and how to get the best price when you sell. For an instant figure, use our free gold calculator.
18ct gold contains 75% pure gold — the remaining 25% is made up of other metals such as silver, copper, or palladium. It's hallmarked with the number 750 and is widely used in fine jewellery across the UK and Europe.
Because of its high gold content, 18ct is softer and more lustrous than 9ct gold, and commands a significantly higher price per gram. It's commonly found in:
To understand more about gold purity and hallmarks, see our gold purity guide and British hallmark guide.
The value of 18ct gold is based on three things: weight, purity, and the live gold spot price.
Formula: Weight (troy oz) × 0.75 × Spot price (£/troy oz)
Here are some worked examples based on a spot price of £2,500 per troy oz:
Gold prices change daily — check our live gold price page for the current spot price, then use our gold calculator to get an up-to-date figure for your exact weight.
The value of 18ct gold per gram fluctuates with the gold spot price. As a rough guide:
These are the melt values — the theoretical maximum based on pure gold content. Buyers will offer a percentage of this to cover their costs. At 888 Bullion, we offer highly competitive rates for 18ct gold.
The offer you receive will be a percentage of the melt value. This varies depending on:
If you're unsure whether your piece is 18ct, we offer XRF metal testing in London — instant, non-destructive purity verification.
Here are typical weights for common 18ct gold jewellery items and their approximate melt values at £2,500/oz spot:
These are estimates only — use our gold calculator with your exact weight for a precise figure.
18ct gold is exactly twice as pure as 9ct gold (75% vs 37.5%), so per gram it's worth approximately twice as much. A 10g 18ct gold ring is worth around £600 at current prices, compared to around £300 for the same weight in 9ct.
See our full comparison in our gold value guide or use the calculator to compare carats side by side.
At 888 Bullion, selling your 18ct gold is straightforward:
Gold prices have been at or near historic highs in recent years, making it an excellent time to sell unwanted 18ct gold jewellery. Read our guide on the best time to sell gold in the UK for more context.
Look for a hallmark stamped on the piece — 18ct gold is marked with 750. Our hallmark guide explains all UK gold marks. If there's no hallmark or you're unsure, our XRF testing service can verify it instantly.
Yes — significantly. 18ct gold contains twice the gold content of 9ct, so it's worth approximately twice as much per gram at the same spot price.
For scrap purposes, no — only the gold content matters. However, designer 18ct pieces (e.g. Cartier, Tiffany) may have additional collector value worth exploring before selling as scrap.
In-person sales at our Hatton Garden office are paid the same day. Postal sales are paid within 24 hours of receipt and verification.
Yes, but they'll be valued separately. We recommend sorting your gold by carat before bringing it in to speed up the process.
Ready to find out what your 18ct gold is worth? Use our free gold calculator for an instant estimate, or get a quote to sell your gold today.
Also see: How Much Is My Gold Worth? | How Much Is My 9ct Gold Worth? | Scrap Gold Calculator | 18ct Gold Guide 2026
